Throughout the world there is a growing interest in endless belt filters as aforesaid for dewatering and/or extracting vast numbers of materials, specifically but not exclusively fine coals, and mineral ores.
There is a practical limit to the length to which one can construct and endless belt filter, usually determined by the length of building in which it is to be housed. Accordingly attempts have been made to make the filter belts wider, but in practice the maximum width so far achieved has been of the order of four meters, and even so these have been difficult to operate effectively.
The problem with these wide filters are twofold.
Firstly, in order to achieve a reasonable area of filter belt, they still have to be built to lengths up to 20 meters. This normally means that extreme difficulties are encountered in guiding the filter belt. Secondly, substantial practical difficulties arise in attempting to support conventional rollers of four meters or greater axial length. Such rollers consist of tubular units supported only at their extremities and they are necessary for guiding and tensioning the belt.
An object of the present invention is to provide an endless belt filter construction by which both of these disadvantages may be obviated or minimised.